Racking mechanism for knitting machines



May 3, 1949. E. J. BERGER ET AL BACKING MECHANISM FOR KNITTING MACHINES 2 Sheets-Sheet 1 Filed Oct. 15, 1947 WITNESSES INVLNIORS BY W1 W ATTORNEYS.

May 3, 1949. E. J. BERGER ET AL BACKING MECHANISM FOR KNITTING MACHINES 2 Sheets-Sheet 2 Filed Oct. 15, 1947 INVENTORS: 5722M Jfler er (Q flown/(Z16 65"?) BY a Z ATTORNEYS.

y I w g Patented May 3, 1949 BACKING MECHANISM FOR KNITTING MACHINES Emil J. Berger and Howard K. West, Lansdale, Pa., assignors to The Dexdale Hosiery Mills, Lansdale, Pa., a corporation of Pennsylvania Application October 15, 1947, Serial No. 779,948

6 Claims.

This invention relates to racking mechanism useful in connection with knitting machines of the straight type such as are ordinarily employed in the production of flat fashioned hosiery blanks, to forwardly and reversely turn the screw spindles whereby the narrowing point combs and the yarn carrier stops are shifted back and forth as required to shape difierent portions of the blanks, and also to pre-set said point combs and said carrier stops in readiness for operation during these various stages of the knitting.

Our invention is directed in the main toward the provision of racking mechanism for the purpose stated which is simple in construction; which is readily adaptable to existent knitting machines without entailing any radical changes either in their construction or in their normal mode of operation; and of which the motion inducing elements are constructed and arranged for capacity to yield in the event that the narrowing point combs or the yarn carrier stops should, for any reason, become jammed.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein Fig. 1 is a fragmentary view in end elevation, of a straight stocking knitting machine conveniently embodying our invention.

Fig. 2 is a fragmentary view of the machine in front elevation or as seen from the left of Fig. 1.

Fig. 3 is a horizontal section taken as indicated by the angled arrows III-III in Fig. 2; and

Fig. 4 is an exploded view showing certain related parts of the mechanism in juxtaposition.

The knitting machine, insofar as it is shown in Figs. 1-3, is generally speaking, of the construction disclosed in U. S. Patent No. 1,982,991 granted to Kenneth Howie on Dec. 4, 1934. The longitudinally-extending main cam shaft III of the machine is journalled in suitable bearings afforded by the side frames of the machine near the bottom, one such side frame being indicated at II. Likewise rotatively supported in the side frames I I near the top and at the back is a horizontal control shaft I2, and immediately thereabove, the screw spindle I3 for the yarn carrier stops (not shown). Through interposed connections controlled from the chain (not shown) of the machine, the control shaft I2 is stepped about through a complete revolution for each knitting cycle in the usual manner. The spindle I3 is provided with two ratchet wheels with oppositely disposed teeth arranged to be picked respectively by pawls I4 and Ida carried by members oscillatable about said shaft. Suitable mechanism (not shown) are of course provided in the machine for selectively controlling the activity of the pawls I4, Ma and I8, IBa by which the spindles I3 and IE are racked in opposite directions as required during certain phases of the knitting. This mechanism may be like the mechanism provided for a similar purpose in the Howie patent, supra. The fashioning mechanism is partly shown at I5 with its screw spindle I6 for shifting the narrowing point combs (not illustrated), said spindle being journalled in dipping arms whereof one is indicated at IT. Like the yarn carrier stop spindle I3, the spindle I6 is provided with a pair of oppositely arranged ratchet wheels which are adapted to be picked respectively by pawls i8 and I8a. The pawls I4, Ma and I8, Ilia, are actuated through metallic tapes I9, 20 and M, 22 by a lever 23 which is fulcrumed on a fixed stud 24 extending laterally from the side frame II. A screw bolt 25 adjustable in a projection 26 on the side frame I I serves to limit the upward movement of the lever 23.

In adapting our invention to a knitting machine such as briefiy described above, we have provided the fulcrum boss of the lever 23 with a longitudinal slideway 21 (see Fig. 4) in which a clutch key 28 is confined by two retainer plates 28. The key 28 has a stud projection 30 for engagement by a finger 3| pendant from a rock shaft 32 which is rotatively supported in a fixed bearing bracket 33 on the frame I I. Also secured to the rock shaft 32 is an upwardly reaching finger 34 which is urged toward a cam disk 35 on the control shaft I2 through influence of a torsion spring 35 upon said rock shaft. A light tension spring indicated at 3'! serves to maintain the stud 3|! of key 28 yieldingly engaged with the finger 3!. As shown, the disk 35 has an annular face ridge 38 with circumferentially spaced notches 39, 39a and 39b, 390 for action upon the bevelled cam end 49 of finger 34 as and for a purpose later explained. Loosely mounted on the stud 24 to opposite sides of the lever 23, are arms M and 42 respectively with rollers 43 and M which are adapted to ride the peripheries of rotary cams 45 and 48 on the main cam shaftlfl. Projecting rearwardly from the fulcrum bosses of the roller arms 4i and 42 are lugs 41 and 48 for cooperation respectively with the opposite ends of the clutch key 28 depending upon the direction in which the latter is shifted. Adjustable in the lug projection 48 is a screw stud 48a with which the key 28 is intended to directly contact; said stud being securable in adjusted positions by a set screw 48b. The roller arms 4| 3 and 42 are formed as bell cranks to the extremities 49 and 50 of which pull springs 5| and. 52 are respectively connected, whereby the rollers 43 and 44 are yieldingly held to the rotary cams 45 and 46 on the main cam shaft I0. Associated respectively with the rotary cams 45 and 46 are concentric circular idling disks 53 and 54. In Fig. 2, these various elements of the racking mechanism are shown in the positions which they occupy during normal knitting, i. e. with the roller 43 of arm 4| bearing on the idling disk 53 and the roller of arm 42 bearing on rotary cam 46. The activity of the racking pawls M, Ma and I8, |8a is intended to be controlled by means, not illustrated which may be identical with the means disclosed for a similar purpose in the Howie patent supra, and has for this reason been omitted from the drawings.

Operation Upon completion and closing of the welt portion of a stocking blank in the machine, the disk 35 is rotatively shifted in the direction of th arrow in Fig. 1 so that the first notch 39 thereof is brought into registry with the cam end 40 of the finger 34. Immediately upon this occurrence the torsion spring 35 will turn the shaft 32 anti-clockwise, whereby, through the fingers 3|, the clutch key 28 will be shifted rightward in Fig. 2. As a consequence, the left-hand end of the key is withdrawn from over the lug 41 of roller arm 4| and its right hand end advanced over the lug 48 of the roller arm 42, the latter being constantly oscillated at this time by the rotary cam 46. In the event that at the moment of shifting, the stud 4811 on roller arm 42 is in the way of the key 28, the torsion spring 35 will allow the finger 3| to yield until the arm 42 has moved to a position where said stud will clear the key and release it. With the key 28 shifted as just explained, movement is communicated by the roller arm 42 to the lever 23, whereby the spindles l3 and I6 are racked to set the yarn carrier stops and the narrowing point combs which they govern inward into position in readiness to effect the usual narrowings in the upper leg portion of the stocking blank. When the yarn carrier stops and the narrowing point combs have been so set, the cam disk 35 is given another rotative shift in the same direction as before for advance of its notch 39 beyond the cam end 40 of finger 34 whereby the key 28 will be returned to its original position. Upon each shift of the main cam shaft In to the right as ordinarily to effect the upper leg narrowings, the rotary cam is transposed to the plane of the roller 43 of the arm 4| which is consequently actuated and its movement communicated to the lever 23 for rotation of the spindles I3 and It as required for the narrowing. Soon after completion of a predetermined number of narrowings, the disk cam 35 is further rotatively shifted to position its notch 39a for another actuation of finger 34, with consequent shifting of the key 28 to again connect the lever 23 to the roller arm 42 whereby the spindles l3 and Hi once more turned to set the yarn carrier stops and the narrowing point combs in readiness for fashioning of the calf portion of thestocking blank. This second narrowing is eventually accomplished like the first mentioned series through rightward shifting of the main cam shaft l0 whereby the screw spindles l3 and I6 are turned as required through movements imparted to the lever 23 by the roller arm 4|. The remaining notches 39b, 390 in the disk 35 determine similar actuations of the screw spindles l3 and IE to set th yarn carrier stops and the narrowing point combs in readiness for the fashioning respectively of the heel and the toe portions of the stocking blank in precisely the same manner as above described for the upper leg and calf narrowings.

From the foregoing it will be seen that the lever 42 is utilized for the operation of the two spindles l3 and E6 to pre-set the yarn carrier stops prior to each fashioning phase of the knitting, while the lever 4| is utilized for the operation of said spindles during the fashioning phases. It is also to be particularly noted that the active movements of the roller arms 4| and 42 are induced by the pull springs 5i and 52 rather than by direct action of the rotary cams 45 and 46. Thus, in the event that for any reason the screw spindles l3 and It or any of the instrumentalities governed by them become jammed, the lever 23 will be allowed to yield and thus prevent injury to or breakage of the involved parts.

Having thus described our invention, we claim:

1. Racking mechanism for a knitting machine having a main cam shaft and a narrowing screw spindle, said mechanism including a ratchet wheel on the spindle, a pawl bodily oscillatable about the spindle to act upon the ratchet wheel, a lever fulcrumed to rock on a fixed axis, interposed operating connections between the pawl and the lever, a pair of rotary cams on the main cam shaft, two arms adapted to be motivated by the respective cams, and clutch means for selectively connecting the lever to one or the other of the two arms for actuation thereby.

2. The invention according to claim 1, further including a control shaft, and means controlled from said control shaft for actuating the clutch means.

3. The invention according toclaim 1, wherein the two arms are .fulcrumed on the same axis with the lever, and wherein the clutch means comprises a key which is confined to a longitudinal slot in the fulcrum boss of the lever and which is shiftable in said slot for selective engagement with the two arms.

4. The invention according to claim 1, wherein the two arms are fulcrumed on the same axis with the lever and provided with rollers to run in peripheral contact with separate rotary cams on the main cam shaft, wherein spring means yieldingly urge the arms toward the cams, and wherein the clutch means comprises a key which is confined to a longitudinal slot in the fulcrum boss of the lever and which is shiftable endwise in said slot for selective engagement with lug projections on the fulcrum bosses of the two arms.

5. Th invention according to claim 1, wherein the two arms are fulcrumed on the same axis with the lever and provided with rollers to run in peripheral contact with the rotary cams on the cam shaft; wherein spring means yieldingly urge the arms toward the cams, wherein the clutch means comprises a key which is confined to a longitudinal slot in the fulcrum boss of the lever and which is shiftable endwise in said slot for selective engagement with lug projections on the fulcrum bosses of the two arms, and wherein the machine is provided with a control shaft; and further including a control shaft, a disk on the control shaft having circumferentially spaced cam notches; a finger aifixed to a rock shaft with its end in the path of the cam notches in the disk, spring means yieldingly urgingthe finger toward the disk, a second finger on the 5 rock shaft extending oppositely from the first finger and adapted to laterally engage a stud projection on the clutch key, and a light spring means influential upon the slide to maintain the stud thereon in engagement with said second finger.

6. The invention according to claim 1, wherein the main cam shaft as longitudinally shiftable for narrowing purposes, wherein the two arms are respectively provided with rollers for peripherally engaging the respective rotary cams on the cam shaft, wherein spring means influence the arms to maintain the rollers in engagement with the cams, wherein idling disks are respectively associated with the cams, and wherein the cams and disks are so arranged that one cam is rendered operative upon the corresponding roller arm when the cam shaft is in its normal position 6 and the other cam is rendered operative upon the other roller arm when the cam shaft is in its shifted position.

EMIL J. BERGER.

HOWARD K. WEST.

REFERENCES CITED The following references are of record in the file of this patent: 

